Digital Myxoid Cyst
Author: Dr Olivia Wooler
Chief Editor: Dr Daniel Keith
Digital myxoid cysts are benign cystic lesions that occur on the fingers and, less frequently, the toes. They are typically found between the distal interphalangeal joint and the nail, and contain a jelly-like fluid. Their exact cause is unknown, but they likely form due to leakage of synovial fluid following trauma or chronic wear and tear. They are usually asymptomatic.
Macroscopic Appearance
Macroscopically, digital myxoid cysts are skin-coloured or translucent, dome-shaped nodules
They most frequently occur on the middle and index fingers of the dominant hand
Mechanical stress on the nail may lead to nail dystrophy, commonly resulting in a longitudinal groove or depression in the nail plate (arrow)
The jelly like fluid contained in the cyst can sometimes leak or be expelled from the cyst, which can sometimes be blood stained
As they contain fluid, digital myxoid cysts can be transilluminated with a light
Dermoscopic Appearance
Below is an example of a digital myxoid cyst under dermoscopy (unannotated and annotated) in Fitzpatrick Skin Type 2.
Dermoscopic examination typically shows fine arborising telangiectasia - blood vessels with distinct tree-like branching (shown by the white arrows).
